Cutter for condenser tubes



1933. w. F. OBERHUBER 1,922,630

CUTTER FOR CONDENSER TUBES Filed July 17, 1931 liiiilz Patented Aug. 15, 1933 UNITED STATES FATENT GFFIfiE to Franklin Development Company, Philadelphia, Pin, a Corporation of Fennsylvania Application July l7, 1931. Serial No. 551,447

8 Claims.

My invention relates to a rotary pipe cutter intended for any use to which it may be adapted but believed to have perhaps its best application for cutting condenser tubes from condensers preparatory to the replacement of the condemned tubes, the cutting of a tube being effected while inserting one end of the cutter into the open end of the tube.

Gne purpose of the invention is to provide an inexpensive cutter of the character indicated, easy and inexpensive to manufacture and well adapted to the intended service.

A further purpose is to longitudinally position the cutting tool of a rotary cutter of the character indicated by a collar presented to the open end of the tube being cut.

A further purpose is to determine the radial extension of the cutting edge 0:" the rotary tool by the inward extension of the carrier of the tool with respect to a surrounding collar forwardly supported against the open end of the tube being out.

A further purpose is to radially positively advance and retract the cutting edge of a cutting 5 tool by longitudinal inward and outward movements of the tool carrier into the open end of the pipe to be out.

A further purpose is to provide a novel annular offset ranging of the cutting edges of three 0 cutting tools to secure a straight cut through the tube.

A further purpose is to extend th cutter mount rearwardly beyond its pivotv point to form a heel and to wedge operate both the cutter end and the heel of the cutter to positively control the position of the cutter.

A further purpose is to spring retract the cutters and to utilize part of the space within the spring to receive control parts for the cutters.

Further purposes will appear in the specification and in the claims. a

I have preferred to illustrate one form only of my invention, selecting a form that is not only practical, efficiently simple and inexpensive, but which at the same time well illustrates the principles of the invention.

Figures 1 and 2 are side elevations of a cutter embodying a desirable form of the invention, the cutter being shown in position of use at different phases of a cutting operation, respectively the initial phase in Figure 1 and anintermediate phase in Figure 2, with the pipe and pipe mounting shown in section.

' Figure 3 is a view corresponding to Figure l,

except that the cutter mechanism shown full in Figure l is in longitudinal section in Figure 3.

Figures 4: and 5 are sections taken upon Figure 8 on lines l4 and 55 respectively.

Figure 6 is a fragmentary, longitudinal section corresponding to a portion of Figure 3, with parts of the tool carrier broken away to disclose the ends of the cutting tools.

Fi ure 7 is a longitudinal section corresponding generally to Figure 3, but with the parts at a diiierent phase of operation, Figure 3 showing the initial and Figure 7 the final phase of a cut.

Figures 8 and 9 are top and bottom fragmentary plan views illustrating a partially diagram- 7 Inatic detail feature and showing the cutting ends of the tools and the alinement positions thereof.

Like numerals refer to like parts in all fig ures.

Describing in illustration and not in limitation and referring to the drawing:-

One of the widest applications for the present invention is believed to be in cutting out condemned condenser tubes for replacements and in the illustration the tube 10 fastened in the wall so 11 of a condenser or the like has received a cutter 12 embodying a desirable form of the invention.

The cutter comprises a plug 13, a collar 14 and one or more tools 15, each tool seating in a longitudinal groove 16 of the plug and 1ongitudinally interlocking with the collar 14.

The collar is desirably made in two parts, a rearward portion 14 that makes the longitudinal interlocking connection with the tool or tools and a forward portion 14 that forms a guiding connection with the outside of the plug and is rigidly fastened as at 18 to the ring member 14.

The forward portion 14 of the collar maintains the ring 14 in angular alinement, shields the ring 14' from engagement with the open end of the tube 10 and is slotted on its interior at 19 to house an outwardly extending intermediate portion 20 of the tool.

v The collar 14 is removably mounted on the ring 14 and is interchangeable with similar or difierent collars of different or the same lengths to accommodate any difference in the desired point of cutting or/and in the surface presented by the condenser or the like to the tool at the tube end.

The forward movement of the collar along the plug is desirably limited by an intermediate rearwardly directed abutment 21, which may be suitably an annular shoulder obtained by reducing the rearward portion of the plug as compared to the forward portion thereof.

The forward end of the collar normally fits against the rearwardly directed shoulder 21 of the plug, he plug being adapted to slide forwardly in the collar, preferably against the fairly heavy retraction of a spring 22.

As illustrated a flange ring 23, pinned at 24 to the rearward end of the plug has a forwardly directed hub portion 25 that fits inside the rearward end of the spiral spring 22 which is thus compressed between the flange and the ring 14, thereby maintaining the plug resiliently rearwardly retracted with respect to the ring and the tool or tools longitudinally connected to the ring, the shoulder 21 of the plug normally abutting against the forward end of the collar 14 The bottom or bottoms of the groove or grooves 16 that house the tool or tools 15 are progressively deeper from an intermediate point 26 toward the forward and rearward ends thereof, the sloping bottom of the forward portion of the groove definitely limiting the inward extension of the cutting head 27 of the tool while the reversely sloping bottom of the rearward portion of the groove engages the bottom of the rearward extension 28 of the tool to definitely limit the outward position of the head 27.

The tool outwardly fulcrurns on the ring 14 so that the position of the tool head 27 with respect to its distance from the plug axis is definitely determined by the longitudinal position of the col- 14 along the rearward portion of the plug 13.

It, will be seen that each tool is laterally guid ed by the sides of the groove seat and outwardly guided by the sloping bottom thereof, the plug angularly turning about its fulcrum connection with the collar when there is longitudinal move ment of the plug with respect to the collar.

Preferably the cutter is rovided with three cutting tools, each having its groove seat 16 in the plug 13, the grooves and tools being uniformly angularly spaced around the plug.

One feature of the invention is directed to the form and arrangement of the cutting faces presented by the tools which adapt the cutter as a whole to produce a cut that is substantially square with the tube at both sides of the cut, and to make the cutting duty on the three tools during cutting substantially equal.

Two of the tools present oppositely directed cutting faces 29 and so square to the tube at opposite sides of the out while the third tool presents a bevel cutting face 31 to cut away the metal intermediate the heads 29 and 3O operating at the sides of the cut.

While the connection between the collar 14; and tools 16 may be of any form adapted to prevent longitudinal movement between the collar and tools and to support the tools from radially outward movement at the connection, a preferred form of connection is that illustrated.

In the illustration the rearward portion 14' of the collar comprises a ring having an inwardly directed annular head '32 that fits a transverse groove 2-3 in an enlarged shank portion 34 of the tool.

The annular head 32 is transversely slotted at to porn i easy assembly of the head and tool, the collar being in assembly turned to bring the slots 35 into registry with the shanks of the tools, then slid to proper longitudinal position, that in which the head registers with the transverse slot 35, and turned circumferential- The operator presses the rotating plug into the open tubes, each time progressing the plug gradually inwardly to outwardly wedge the cutting heads of the tools until the out is complete, the springs retracting the plugs rearwardly when the pressure is removed, the rearward retraction of the plug effecting wedge inward retractions of the cutting heads of the tools, permitting easy retraction of the cutter from the cut tube.

lhe groove seats for the tools are provided vith a clearance space 3'7 on the forward side of the tool.

ihis space receives the cuttings of the tool and does not affect the guiding connection between the tool and plug, the plug engaging the back of the head of the tool for the full depth of the groove and also engaging the bottom of the head and a short distance at 38 on the front of the head.

It will be seen that the chamfer at 37 does not extend to the bottom of the groove, and the forward support presented to the tool head below the eharnfer and near the bottom of the groove cooperates with the rearward support presented to the head at the upper edge of the groove to support the cutting tool from twisting on its own axis.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire 'to secure by Letters Patent is:

1. In a cutter of the character indicated, a plug, a tool and a collar, the plug longitudinally movable with respect to the collar, having a forward portion for insertion into the tube to be cut and a longitudinal outwardly directed groove along said forward portion and for some distance of its length rearwardly thereof, the bottom of the groove sloping inwardly toward the plug axis from an intermediate portion of its length toward its forward and outer ends, the tool being housed in the groove and having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the collar having a longitudinally interlocking connection with the tool at an intermediate point thereof and th tool having a rearwardly extending portion engaging the bottom of the rearward portion of the groove to positively retract the tool head inwardly toward the plug axis as the plug moves rearwardly with respect to the collar.

2. In a cutter of the character indicated, a plug, a tool and a collar, the plug longitudinally movable with respect to the collar, having a diam eter to loosely fit interior of the tube to be out, having a forward portion for insertion into the tube to be out and a longitudinal outwardly digroove along said forward portion and for some distance of its length rearwardly thereof, the bottom of the groove sloping inwardly toward the plug axis from an intermediate portion of its length toward its forward and outer ends, the

tool being housed in the groove and having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug, the collar having a longitudinally interlocking connection with the tool at an intermediate point thereof and the tool having a rearwardly extending portion engaging the bottom of the rearward portion of the groove to positively retract the tool head inwardly toward the plug axis as the plug moves rearwardly with respect to the collar, in combination with an abut ment on the plug toward the rearward end thereof and a spring compressed between the abutment and the collar.

3. In a cutter of the character indicated, a plug, a tool and a collar surrounding the plug, the plug movable longitudinally of the collar having a longitudinal groove housing and guiding the tool with respect to the spacing of the cutting portion thereof from the plug axis, the collar longitudinally interlocking with the tool and supporting an intermediate part of the tool from out ward movement, and the sliding connection between the plug and tool at the forward end of the tool limiting the inward position of the cutting portion of the tool with respect to the outside of the plug and the connection between the tool and plug at the rearward end of the tool rearwardly from said intermediate part cooperating with the collar to limit the outward positions of the cutting edge of the tool with respect to the plug.

4. In a cutter of the character indicated, a plug, a tool and a collar, the plug longitudinally movable with respect to the collar, having a forward portion for insertion into the tube to be cut and a longitudinal outwardly-directed groove along said forward portion and for some distance of its length rearwardly thereof, the bottom of the groove sloping inwardly toward the plug axis from an intermediate portion of its length toward its forward end, the tool being housed in the groove and having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the collar having a longitudinally interlocking connection with the tool, the said collar being two-part, a rearward part having an annular head fitting a transverse recess of the tool and the forward part having an interior outward slot registering with the groove and housing an outwardly extending portion of the tool.

5. In a cutter of the character indicated, a plug, a tool and a collar, the plug longitudinally movable with respect to the collar, having a forward portion for insertion into the tube to be cut and a longitudinal outwardly directed groove along said forward portion and for some distance of its length rearwardly thereof, the bottom of the groove sloping inwardly toward the plug axis from an intermediate portion of its length toward its forward end, the tool being housed in the groove and having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the said collar including an annular head fitting a transverse recess of the tool, and the annular inwardly directed head having a transverse recess to pass the tool at one angular position of the collar with respect to the tool.

6. In a cutter of the character indicated, a plug, three tools and a collar, the plug longitudinally movable with respect to the collar having a diameter to loosely fit the interior of the tube to be out, having a forward portion for insertion into the tube to be cut and longitudinal outwardly directed grooves along said forward portion and for some distance of its length rearwardly thereof, the grooves having progressively variant depths along the said forward portions with the groove bottoms progressively approaching the plug axis from an intermediate portion of the groove toward its forward end, the tools being housed in the grooves, one tool in each groove and each tool having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the collar having longitudinal interlocking connections with the tools, and the tools having extensions in said grooves rearwardly of the collar, the bottoms of the grooves progressively approaching the plug axis from the collar rearwardly, and the engagements between the plug and extensions limiting the outward positions of the cutting faces of the tools and retracting the cutting faces inwardly when the plug is retracted longitudinally rearwardly through the collar.

7. In a cutter of the character indicated, a plug, three tools and a collar, the plug longitudinally movable with respect to the collar having a diameter to loosely fit the interior of the tube to be out, having a forward portion for insertion into the tube to be cut and longitudinal outwardly directed grooves along said forward portion and for some distance of its length rearwardly thereof, the grooves having progressively variant depths along the said forward portions with the groove bottoms progressively approaching the plug axis from an intermediate portion of the groove toward its forward end, the tools being housed in the grooves, one tool in each groove and each tool having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the collar having longitudinal interlocking connections with the tools, and the said collar being two-part, a rearward part having an annular head fitting transverse recesses of the tools, and a forward part having interior outward slots registering with the grooves and housing outwardly extending portions of the tools.

8. In a cutter of the character indicated, a plug, three tools and a collar, the plug longitudinally movable with respect to the collar having a diameter to loosely fit the interior of the tube to be cut, having a forward portion for insertion into the tube to be cut and longitudinal outwardly directed grooves along said forward portion and for some distance of its length rearwardly thereof, the grooves having progressively variant depths along the said forward portions with the groove bottoms progressively approaching the plug axis from an intermediate portion of the groove toward its forward end, the tools being housed in the grooves,

one tool in each groove and each tool having a cutting head toward the forward end of the plug presenting a cutting edge outwardly from the plug and the collar having longitudinal interlocking connections with the tools, and the collar having an annular head having transverse recesses adapted to register with the grooves and to pass the rearward portions of the tools and the tools at one angular position of the collar being adapted to slide out of the collar.

WILLIAM F. OBERHUBER. 

